Turbine construction



March 29, 1966 i J. M. DEsMoND TURBINE CONSTRUCTION Filed Jan. l5, 1964 United States Patent O 3,243,158 TURBINE CGNSTRUCTION James M. Desmond, Granby, Conn., assignor to United Aircraft Corporation, East Hartford, Conn., a corporation of Delaware Filed Jan. 15, 1964, Ser. No. 337,905 7 Claims. (Cl. 253-39) This invention relates to a gas turbine and particularly to a containment for parts of a turbine disc or blades in the event of failure of the rotor.

One feature of the invention is a ring surrounding the gas path through the turbine and in a position to be engaged by fragments in the event of a rotor failure. Another feature is a ring made of a flexible resilient material and so mounted as to absorb the large amounts of energy in the yfragments so that they will not break through the surrounding casing. One feature of the invention is the support of the containment ring or rings so that they may be distorted when engaged by fragments of the rotor thereby having a greater absorptive capacity. Another feature is the support of the containment ring or rings within and in spaced relation to the casing and in such a way that the ring is normally held in concentric relation to the casing.

One feature of the invention is the support of the containment ring in such a way that the latter may also support the usual shroud ring surrounding the row of turbine blades.

Other features and advantages will be apparent from the specification and claims, and from the accompanying drawings which illustrate an embodiment of the invention.

FIG. 1 is a longitudinal sectional view through a part of the turbine, the section in part being along the lines 1 1 of FIG. 2 and FIG. 3.

FIG. 2 is a developed detail substantially along the line 2 2 of FIG. l with a portion broken away.

FIG. 3 is a developed detail substantially along the Aline 3 3 of FIG. 1.

FIG. 4 is a fragmentary view similar to FIG. 1 along a section line 4 4 of FIG. 2.

FIG. 5 is a fragmentary view similar to FIG. 1 substantially along the line 5 5 of FIG. 3.

The turbine has a casing 2 which surrounds the turbine rotor 4. The rotor includes a disc, not shown, to the periphery of which a plurality of blades 6 are attached. A turbine of the basic construction shown in this application is described in the patent to Savin 2,747,- 367. A forward portion 8 of the casing surrounds and supports a row of turbine vanes 10 defining nozzles through which gas flows to impinge on the blades for turning the rotor. The attachment of the vanes within the casing portion 8 is not a part of the present invention.

Surrounding and in radial alignment with the row of blades 6 is a containment ring 12 in the form of a cylinder concentric to and spaced radially inwardly from the casing 2 to constitute a lining for the casing. An annular spring 14 located between the containment ring and the casing serves to hold the containment ring in concentric position. The spring 14 may be held in place by a spacer ring 16 attached to the ring 14 and resting on the inner periphery of the casing. The ring 16 has a radial flange 18 engaging with a ange 20 projecting inwardly from the casing 2 to locate the ring 16 axially in the caslng.

A shroud ring 22 is supported in concentric relation to the containment ring 12 and in radial alignment with the turbine blades. A circular spring 24, U-shaped in cross section and located between the shroud ring and the conice tainment ring, holds the shroud ring in concentric relation to the containment ring and therefore in concentric relation to the rotor. The shroud ring has radially outwardly extending lugs 26 at its forward end to engage in radial grooves 2S on a disc 30. The shroud ring has other lugs 32, FIG, 4, at its rearward end engaging the inner ends of radial notches 34 formed in the inwardly projecting ange 20, as shown in FIG. 3. The inner end of the flange 20 has a rearwardly extending cylindrical flange 35 thereon, as shown, interrupted where the radial notches 34 occur.

The disc 30 is clamped between the casing 2 and the portion 8 and serves to engage the outer shroud 36 on each of the Vanes 10 to hold the vanes in axial position. The grooves 28 also engage with cooperating lugs 38 on the forward end of the containment ring 12 thereby further serving to hold the containment ring in concentric relation to the casing although permitting movement of the ring radially outward at any particular portion of the ring in the event that the shroud ring and thence the containment ring is hit by fragments of the rotor in the event of ruptura The rearward end of the containment ring also has lugs 40 which engage with alternate notches 34 in the inwardly extending ange 20, as shown in FIGS. l and 2.

Extending downstream from the iiange 20 and located within the casing 2 are concentric containment rings 42 and 44, the latter being smaller in diameter and located in spaced radial relation to the larger ring 42. The larger ring 42 is radially spaced inwardly of the casing and constitutes an extension of the lining for the casing. The forward end of the rings 42 and 44 have lugs 46 and 48, FIG. 4, respectively, which engage with alternate notches 34, fitting, as will be apparent, in the notches not occupied by the lugs 40 of ring 12. The forward end of the containment ring 44 has a notch 50 in one corner to receive the trailing edge of the lugs 33 on the shroud ring 22 and the trailing edge of the flange 35 so that this containment ring 42 also functions as an extension of the outer wall of the gas path through the turbine. At the downstream end of the rings 42 and 44 they are held in concentric relation to the casing by a supporting disc 52 clamped between a ange 54 on the casing and a cooperating downstream portion 56 of the casing. The disc 52 has a projecting rib 58 thereon having notches 60 therein cooperating with lugs 62 on the containment ring 42 and lugs 64 on the containment ring 44.

In this way the containment rings 12, 42 and 44 are supported radially inwardly of the casing in such a way that should the turbine rotor fail and fragments thereof are thrown outwardly by centrifugal force, they will irnpinge on either the shroud ring 22 or the containment ring 44. Because of the energy in these fragments they may carry through the shroud ring 22 and into contact with the ring 12 or into or through the ring 44 to engage the ring 42. These rings 12, 42 and 44 are made of a tough resilient material preferably steel although they might well be made of a non-metallic material such as Fiberglas. These rings being resilient and flexible are so mounted that they are free to move radially outward into Contact with the casing by distortion or rupture of the positioning lugs thereon and in this movement will absorb enough of the energy in the fragments of the rotor such that these fragments will not have enough kinetic energy to break through the casing 2.

Obviously this construction is a safety feature for protecting the structure surrounding the turbine. If it is incorporated in a turbine aircraft engine it will protect the remainder of the aircraft from damage by the fragments from the engine or if in a stationary Powerplant `it will protect personnel or other machinery or apparatus located near to the powerplant.

It is to be understood that the invention -is not limited to the specific embodiment herein illustrated and described, but may be used in other ways without departure from its spirit as defined by the following claims.

I claim:

1. In a turbine construction, an outer casing, a row of vanes within the casing, a row of blades within the casing downstream of the vanes, a rotor disc on which the blades are mounted, a shroud ring located at the periphery of the row of blades and spaced radially in- Ward of the casing, and a containment ring located Within the casing between the casing and the shroud ring and in spaced radial relation thereto in a position to be engaged by fragments of the blades or the disc in the event of failure, said containment ring being mounted so as to yield radially into contact with the casing.

2. A turbine construction as in claim 1 in which said casing has a set of radial notches thereon and said ring has lugs at one edge to engage with the notches on the casing.

3. A turbine construction as in claim 1 in which said casing and said ring have cooperating notches and lugs to hold the ring concentrically within the casing.

4. A turbine construction as in claim 1 in which a second ring is provided substantially in axial alignment with the first ring and downstream thereof, said second ring being within and spaced radially of the outer casing.

5. A turbine construction as in claim 4 in which the rst and second rings have lugs at adjacent edges engaging in notches in a rib on the casing to hold the rings in axial alignment.

6. A turbine construction including, a casing having a varied stator therein, a rotor including a disc having a row of blades on its periphery mounted for rotation within the casing, a shroud ring in the form substantially of a cylinder located within and spaced from the casing and in radial alignment with the blades, and a lining for a part of the casing to protect it from fragments in the event of failure lof the rotor, said lining including at least one containment ring of substantially cylindrical configuration located between the shroud ring and the casing and in radially spaced relation to both, said containment ring and said casing having cooperating means located at each end of the ring for supporting said ring in radially spaced relation to and Within the casing.

7. A turbine construction as in claim 6 in which the cooperating means are radially extending grooves on the casing and cooperating lugs at the end of the ring said lugs being severable under severe load to permit the ring to move radially at a selected point on the ring.

References Cited by the Examiner UNITED STATES PATENTS 2,987,296 6/1961 Ferguson 253-59 2,999,667 9/1961 Morley 253-39 3,146,992 9/1964 Farrell 253-39 FOREIGN PATENTS 975,879 10/ 1950 France. 790,854 2/ 1958 Great Britain.

SAMUEL LEVINE, Primary Examiner.

E. A. POWELL, JR., Assistant Examiner. 

1. IN A TURBINE CONSTRUCTION, AN OUTER CASING, A ROW OF VANES WITH THE CASING, A ROW OFE BLADES WITHIN THE CASING DOWNSTREAM OF THE VANES, A ROTOR DISC ON WHICH THE BLADES ARE MOUNTED, A SHROUD RING LOCATED AT THE PERIPHERY OF THE ROW BLADES AND SPACED RADIALLY INWARD OF THE CASING, AND A CONTAINMENT RING LOCATED WITHIN THE CASING BETWEEN THE CASING AND THE SHROUD RING AND IN SPACED RADIAL RELATION THERETO IN A POSITION TO BE ENGAGED BY FRAGMENTS OF THE BLADES OR THE DISC IN THE EVENT OF FAILURE, AND CONTAINMENT RING BEING MOUNTED SO AS TO YIELD RADIALLY INTO CONTACT WITH THE CASING. 